Pump



E. J. KARP Nov. 8, 1960 PUMP 5 Sheets-Sheet 1 Filed May 22, 1958 lllll Il Il ll Il y; fwn I Nov. 8, 1960 E. .1. KARP 2,959,134

PUMP

Filed May 22, 1958 3 Sheets-Sheet 2 *1 INVENTOR. L) I) N n/aard zzyy BY 9 @5ft/ZS Nov. 8, 1960 E. J. KARP 2,959,134

PUMP

Filed May 22, 1958 3 Sheng-Sheet 3 INVENTOR.

fla/ward If fafj@ United States Patent O PUMP Edward J. Karp, Maywood, Ill., assignor to G. Blakeslee & Co., Chicago, lll., a corporation of Illinois Filed May 22, 1958, Ser. No. 737,098

'3 Claims. (Cl. 10S-103) This invention relates to pumps, and particularly to an improved centrifugal pump employing a rotating impeller.

The improvements of this invention are directed to centrifugal irnpeller-type pumps having particular utility in automatic dishwashing machinery and similar equipment, wherein it is necessary to periodically clean and inspect the dynamic elements of the pump. In brief, the novel aspects of my invention center about an irnproved sub-assembly by which the rotatable impeller and its related seal and shaft elements are removable from the pump housing as a unit. Provision is further made for the removal of such impeller assembly without disturbing the intake and discharge plumbing, the pump housing, and the drive motor. With this arrangement, the rotatable centrifugal impeller, its related bearing means, seals, and means for connecting the same to the drive shaft of a motor are easily and conveniently handled as a unit requiring a minimum disturbance of the installation and producing a maximum of convenience for both inspection and repair.

The main object of this invention is to provide a new and improved centrifugal pump in which the dynamic portions of the pump are removable from the housing as a self-integrated unit.

Another object of this invention is to provide an improved centrifugal pump having improved features of assembly and manufacture leading to economies of production and facilitating the servicing and repair of the pump.

A still further object of this invention is to provide a new and improved centrifugal pump in which the impeller, its Supporting shaft, and related seal assemblies are manually removable from the pump housing without disturbing piping connections, the housing, or the drive motor, thereby promoting the convenience of inspection and field repair.

A still additional object of this invention is to provide a new and improved pump, as aforesaid, which is particularly adapted and useful for automatic dishwashing equipment.

The above and further objects, features, and advantages of this invention will appear to those familiar with the art from the following detailed description and speciiications of a preferred embodiment thereof illustrated in the accompanying drawings.

In the drawings:

Figure l is a -view in sidey elevation with portions broken away to illustrate a typical automatic dishwashing machine in which the pump of this invention finds particular utility;

Figure 2 is a side elevationalview of the improved pump of this invention, showing a portion thereof in cross section, substantially as viewed at 'line 2-2 of Figures 1 and 3, to illustrate the internal arrangement and unique combination of elements according to my invention;

Figure 3 is a view in end elevation with portions thererice of broken away in section substantially at line 3 3 of Figure 2 and looking in the direction of the arrows thereon;

Figure 4 is a view in side elevation showing the impeller assembly and a related retainer ring means for positioning the same within the pump housing according to this invention; and

Figure` 5 is an enlarged partial view in cross section showing a bellows-type seal assembly employed in the impeller unit of Figure 4.

Turning now to the general features and aspects of a typical dishwashing machine 10, as viewed in Figure 1, it will be recognized that such a device, in general, constitutes an endless conveyor 11 trained over sprockets 12, 12 and presenting a plurality of spaced dish-engaging fingers or flight members 13 between which dishes or like articles 14 are supported and carried through suitable washing and rinsing stations within an elongated housing 15. Such a machine preferably includes upper and lower prewash spray stations 16 and 17, respectively, and upper and lower washing sprays 18 and 19 Upper and lower rinse nozzles 20 and 21 and nal rinse nozzles 22 and 2,3 are also provided in tandem succession to the prewash and wash nozzles; conveyor 11 progressing through such stations from left to right, as indicated by arrow A of Figure 1. The pre-wash and wash sprays are supplied from a wash tank 25 serviced by a pump 30, ac-

cording to this invention. ln a like manner, a second pump 30 services rinse tank 31, which supplies rinse water to the several rinse nozzles.

Typically, the wash and rinse tanks 25 and 31 have a capacity of 45 to 60 gallons and the pumps have a delivery capacity of substantially 290 gallons per minute, each of such pumps being driven by a two horse-power (not shown herein).

It is essential in this type of dishwashing equipment that the pump be readily broken down for inspection and cleaning purposes. It is to such general proposition that the present invention is directed with improvements in assembly and construction intended to greatly facilitate the use and operation of a centrifugal pump in this particular or like circumstances.

With reference now to Figure Z, it will be understood that a pump 30, therein illustrated, includes a three-part housing assembly, comprising a cylinder suction or intake chamber portion 35, a torus-shaped impeller chamber portion 36, and a mounting bracket portion or cage 37 providing a closure member for the outer end of the impeller chamber portion.

The cylindrical suction chamber portion 35 (see Figure 3) is provided with an access opening at its outer end closed by a cover plate 40 which is removably held in position by plural holding stud bolt, nut, and lock washer assemblies 41. The plate 40 includes -a substantially cylindrical side Wall portion 42, defined at one end by an outwardly iiared lip portion 43 and an enclosing back wall portion 44. The side wall portion 42 is suitably recessed at 45 to receive an annular O-ring seal member 46 and is ground or otherwise finished to engage an annular seat face 47 formed about the mouth of the chamber housing 35. The back wall 44 of the access plate is further itted with a pair of outwardly projecting ear portions 48, 48, suitably spaced apart and extending into the interior of the suction housing portion 35. An inlet opening 50 dened by inlet or suction flange 51 projects outwardly of one side of the cylindrical suction chamber housing 35; ange 51 being provided with suitable ear portions 52 having holes for receiving bolts or like coupling means employed in a conventional manner for connection with suitable supply line piping 53. The axially innermost end of the housing portion 35 is also provided with an annular ange 54 having an outer end face 55 which mates with an annular shoulder portion 56 on the adjacent end of the impeller case 36.

The impeller case or housing 36 comprises a substantially torus-shaped member open at its inner periphery and terminating in a discharge outlet 60 defined by a surrounding flange '61 for connectinggthe discharge side of the pump to suitable piping, such as shown at 62 in Figure l, for example. To this latter end, suitable openears 64 are provided on opposite sides of flange 61 for vaccepting bolts or like fastening devices, according to conventional practice. The impeller housing 36 isyfurther equipped with a pair of drain plugs 65, as best viewed in Figure 3, for draining the pump of liquid, as desired.

The formation of the casing 36 is substantially symmetrical-with respect to its central axis, except for the discharge -outlet and related discharge flange portion, and is suitably-provided with a second annular shoulder portion 66 on the opposite axial end thereof from the shoulde r 56;A such being interlittingly engaged with an inset shoulder face 70 at the inner axial end of the bracket cage 37.

The shoulder 70 is associated with a first Wall portion 72 of the bracket 37 which serves to define a back enclosure wall for the impeller chamber 73, defined by the impeller case 36; such wall 72 terminating in a cylindrical hub portion 75 equipped with a set screw means '76 for purposes which will appear presently. A plurality of holding bolts 78 extend through and between the flange portion 54 of the intake chamber housing 35 and the wall portion 72 of the cage 37 to hold the three housing portions 3S, 36, and 37 in coaxial assembly, such bolt means 73 being equipped with the usual lockwasher 79 and holding nut members 80. By tightening the nuts 80, fluid tight connection is maintained between the axially abutting housing sections 35, 36, and 37.

The cage 37 is normally cast and includes a plurality of web Wall portions 81 which terminate in an annular mounting flange 82 having bolt openings 83 for mounting the pump to a suitable support or like means.

Mounted Within the pump housing, and particularly the pump case 36 above described, is a rotatable impeller assembly, indicated generally by 85, which includes a substantially cylindrical impeller having curvilinear vanes 87 and a central hub portion 88, according to conventional design, The impeller is fixed by key means 89 to a stub shaft 90 having a shoulder 91 formed by an intermediate enlarged section 92. Impeller 86 is held against shoulder 91 by a holding nut 93 mounted on a threaded outer end portion 94 of the shaft. A retainer ring 95 is concentrically fitted about the shaft portion 92 andengages a shoulder face, defined by a cylindrical collar portion or coupling sleeve 96 formed at the outer end of the impeller shaft.

The sleeve 96 bears a central axial bore receptive of the armature shaft 97 associated with a drive motor (not shown) and is coupled rigidly thereto, as by set screw means 93 and a suitable key member 99. In this manner then, rotational driving of the motor shaft 97 serves to rotatably drive the impeller shaft 90 and attached impeller 86.

The ring 95 is fitted with a suitable O-ring seal 100 which provides sealed engagement with the inside face 101 of the central hub portion 75 of the bracket cage 37; set Screw means 76 being threaded inwardly to engage a depressed area 102 of the ring 95, thereby releasably securing ring 95 in hub 75 together. Thus, ring 95 remains stationary and serves as a spacer to fix the distance between the impeller S6 and shoulder 103 at the inner axial end of the shaft collar portion 96.

This spacing between the impeller and shoulder 103 is important for accommodating a bellows seal assembly 105 which is mounted about the shaft portion 92 and providesa rotatable seal between the impellerchamber andifthe shaft 90, particularly the enlarged portion 92 4 thereof. The ring is further adjustable axially along the stub shaft 90 by the length of the set screw depression 102 to regulate the positioning of the impeller 86 in chamber 73, and more importantly, to regulate the axial compression of the bellows seal assembly 105, as will be described presently.

The seal assembly 105, best shown in Figure 5 of the drawings, preferably comprises an assembly according to the features of Patent No. 2,426,047, issued to Frank E. Payne, on August 19, 1957, and entitled Fluid Seal Unit. Such a seal includes a driving sleeve member 107 having an annular configuration of substantially L-shaped cross section and adapted to engage an adjacent shoulder face 108 of the stationary retainer ring 95. Member 107 is fitted within a concentrically surrounding and substantially annular bellows grommet 110 which is axially collapsible and includes a radially inwardly extending wall portion 111 faced by an annular bearing plate 112 adapted to engage one end of a compression spring 113 disposed between such plate 112 and the inside face ofthe drive sleeve member 107. An annular seal Washer member 115 is disposed concentrically about wall 116 of the sleeve member 107, such being substantially L- shaped in cross section and including a Wall portion 117 which engages the wall portion 111 of the bellows grommet. The Wall portion 117 is integral with an axial extension or lip portion 118 which engages the adjacent face 119 of an annular metal seat member 120, interiittingly mounted about an annular seat ring 121 of neoprene or like resilient material. The ring 121 frictionally engages an adjacent face 122 of the impeller 86 and the shaft portion 92 and provides a fluid tight seal therewith.

With such a construction the spring element 113 serves to provide constant axial thrust on the neoprene seat ring 121 and the related seat member 120, thereby producing positive sealing engagement between the ring 121 and the impeller. Both the seat member 120 and the seat ring 121 rotate with shaft 90 and impeller 85, while a wiping seal contact is established between face 119 on the seat member and the adjacent lip 118 of the wear resistant Washer 115. i

It will be recognized that this type of rotatable seal provides an automatic take-up for the wear of lip 118 on the washer 115 and provides for axial expansion and contraction of the seal to accommodate adjustable positioning of the impeller; the compression of spring 113 being limited by the length of the seal retainer ring 95, as previously noted. Thus, overloading of the seal assembly is provented.

In order to provide cooling of the seal faces of assembly 105, fluid admitting openings 125 are formed in the seal retainer ring 95, as best seen in Figure 2. The provision of such cooling uid greatly prolongs the life of the seal assembly and, as a consequence, tends to minimize seal repair and replacement.

At the left-hand or opposite axial end of the impeller unit 85, as viewed in Figure 2, is an annular suction ring which fits concentrically Within `the housing 35 and resiliently engages the annular flange portion 54, particulanly face 131 thereon. This provides a partial peripheral barrier adjacent the axial outer end of the impeller 86, thereby assisting the same in its pumping action.

The suction ring 130 is further fitted with a manually engageable bail 133 which extends into the interior of suction chamber housing 35 `and is connected to the suction ring by pin means 134,(see Figure 2). The bail 133 fits between the projecting ear portions 48, 48 ex-V tending inwardly of the suction chamber access cover 40. Adjustment of the several retaining stud bolt assemblies 41 move the cover 40 into the suction chamber, serving to adjust the axial positioning of the suction ring 130; the cover pushing the bail member 133 thereby to regulate the axial spacing between the suction ring and theadjacent end of the impeller.

From the foregoing, itn will be recognized that, the,.-

entire impeller assembly S5, including the impeller wheel, the seal assembly, and the stub shaft 90 and coupling sleeve 96, is removable from the interior of the pump housing as a unit by merely removing the inspection cover 40, grasping the bail 1.33 to axially withdraw the suction ring 130, and thereafter withdrawing the impeller unit after loosening the set screws 76 and 98. This leads to remarkable economies Ain production and assembly, as well as improved ease of maintenance 'and inspection. This is particularly gratifying and important in a pump utilized in dishwashing equipment, as previously mentioned, where frequent inspection and cleaning of the pump is necessary. It will be understood also that by so removing the impeller unit, it is not necessary to dislodge the drive motor or disturb the intake or discharge piping connected to the pump housing portions 35 and 36. This feature also produces improved savings of time and labor.

From the foregoing, those familiar with the art will readily recognize and appreciate the merits and features of the present invention and will understand that while I have herein shown and described the same in association with a preferred embodiment of its concepts, nevertheless, numerous changes, modications, and substitutions of equivalents may be made therein without necessarily departing from the spirit and scope of the invent-ion. As a consequence, it is not my intention to be limited to the particulars of the device here-in described and shown, except as may appear in the following appended claims.

I claim:

1. In centrifugal pump means, a housing assembly comprising a suction chamber portion having an outer end and an inner end and an `inlet opening between said ends, said suction chamber portion having at its outer end an access opening and a continuous removable cover plate therefor, an impeller chamber portion having an inner end opening into the inner end of said suction chamber portion and an outer end and a discharge opening between its ends, a closure member at the outer end of said impeller chamber portion having a hub extending outwardly therefrom, an impeller shaft extending through said hub into said impeller chamber portion and provided at its outer end with a coupling member of increased diameter adapted to be releasably coupled to a drive shaft, an impeller secured on the inner end of said impeller shaft within said impeller chamber portion, and impeller shaft seal means on said impeller shaft mounted -in said hub and disposed between said coupling member and said impeller, the latter together with said impeller shaft and coupling member and seal means being removable as a unit from said housing through said inner end of said impeller chamber portion and the outer end of said suction chamber portion.

2. In centrifugal pump means, a housing assembly comprising a suction chamber portion having an outer end and an inner end and an inlet opening'between said ends, said suction chamber portion having at its outer end an access opening and a continuous removable cover plate therefor, an impeller chamber portion having an inner end opening into the inner end of said suction chamber portion and an outer end and a discharge openfing between its ends, a closure member at the outer end of said impeller chamber portion having a hub extending outwardly therefrom, a retainer ring removably mounted in said hub, an impeller shaft rotatably mounted through said ring and extending into said impeller chamber portion, said shaft being provided at its outer end with a coupling sleeve of increased diameter adapted to be releasably secured to a drive shaft and abutting the outer face of said ring, an impeller secured on the inner end of said impeller shaft within said impeller chamber portion, and impeller shaft seal means on said impeller shaft mounted in said hub and disposed between said ring and said impeller, the latter and its shaft and the coupling member and retainer ring and seal means carried by said impeller shaft being removable as a unit from said housing through said inner end of said impeller chamber portion and the outer end of `said suction chamber portion.

3. In centrifugal pump means, `a housing assembly comprising a substantially cylindrical suction chamber portion having an outer end and an inner end and an inlet opening between said ends, said suction chamber portion having at its outer end an access opening and a continuous removable cover plate therefor, a substantially torus-shaped impeller chamber portion having an inner end opening into the inner end of said suction chamber portion and an outer end and a discharge opening between its ends, a closure member at the outer end of said impeller chamber portion having a hub extending outwardly therefrom, a retainer ring -removably mounted in said hub, an impeller shaft rotatably mounted through said ring and extending into said impeller charnber, said shaft being provided at its outer end with a coupling sleeve of increased diameter adapted to be releasably secured to a drive shaft and abutting the outer face of said ring, an impeller secured on the inner end of said impeller shaft within said impeller chamber portion, and impeller shaft seal means on said impeller shaft mounted in said hub and disposed between said ring and said impeller, said seal means comprising yielding means exerting pressure thereon axially of said shaft eifective for holding said seal means in pressure contact with said ring and with said impeller, the latter and its shaft and the coupling member and retainer ring and seal means carried by said impeller shaft being removable as a unit from said housing through said inner end of said impeller chamber and the outer end of said suction chamber.

References Cited in the tile of this patent UNITED STATES PATENTS 1,845,363 'I'hompson Feb. 16, 1932 2,184,349 La Bour Dec. 26, 1939 2,207,371 Blackmore et al July 9, 1940 2,291,760 Rupp c Aug. 4, 1942 2,347,386 Adams Apr. 25, 1944 2,355,390 Murphy Aug. 8, 1944 2,733,682 Langteau Feb. 7, 1956 2,739,536 Schaefer Mar. 27, 1956 2,836,124 Lung May 27, 1958l 2,844,100 Heinicke July 22, 1958 2,900,919 Anderson et al. Aug. 25, 1959 FOREIGN PATENTS 751,696 Great Britain July 4, 1956 1,115,759 France Jan. 16, 1956 

